Applicant's own U.S. Pat. No. 7,154,034, incorporated herein by reference, describes a dielectric fuse cutout cover. The cover protects birds and other animals from electrocution, which may also trigger an over-current condition due to electrical shorts between phases or phase to ground that may cause a power outage.
FIGS. 1 and 2 are reproduced from U.S. Pat. No. 7,154,034 and are used to illustrate a problem that has been reported by linemen in the field using the cover and other types of covers incorporating a vertical slot for a wire.
FIGS. 1 and 2 illustrate a conventional fuse cutout 10. A mounting bracket 12 secures a ceramic or polymer insulator 14 to a wooden utility pole 15 or crossarm used to support high voltage conductors, such as carrying 3-phase 12KVAC or higher. A “hot” wire 16 is attached to one phase. The wire 16 is substantially vertical and typically tapped off an overhead wire running between utility poles. A metal connector 18 electrically connects the wire 16 to a top contact 20 of a blowable fuse 22. The fuse 22 electrically connects to a pivot joint 24 and a bottom connector 26. The bottom connector 26 is connected to another wire (not shown) which may lead to a transformer or any other electrical device or conductor. Opening or blowing of the fuse 22 disconnects the top contact 20 from the bottom connector 26.
A metal hook assembly 28 is fixed to the connector 18 and is used to temporarily support a load break tool for opening the fuse 22. A metal pull ring 30 is physically and electrically connected to the upper end of the fuse 22. By coupling the load break tool to the hook assembly 28 and pull ring 30 and then pulling down on the load break tool, the fuse 22 may be pulled away to safely open the circuit.
A dielectric cover 32, described in Applicant's U.S. Pat. No. 7,154,034, can be installed by a lineman, using a hot-stick, while the wire 16 is connected and energized, since the cover 32 has a rear vertical slot 34 and top hole 36 for the wire 16 that allows the cover 32 to be slid over the cutout 10 and lowered down onto the cutout 10. The cover 32 prevents wildlife, such as birds and squirrels, from coming into contact with the high voltage conducting portions of the cutout 10.
The slot 34 faces the pole 15 or crossarm so the wildlife may be able to access the narrow slot 34 while alighting on the pole or crossarm. The large opening shrouding the hook assembly 28 and pull ring 30 face away from the pole 15 or crossarm and cannot be accessed by the wildlife. So the wildlife is protected.
However, linemen have reported that squirrels are able to push nuts, such as acorns, through the resilient rear slot 34 to fill the area near the wire 16 with the nuts. On the order of 100 nuts have been crammed into the cover 32 by squirrels via the slot 34. This also results in the resilient slot 34 being greatly widened by the nuts. This reduces the ability of the cover 32 to protect the wildlife and reduces the ability of the cover 32 to prevent arcing from a conductor to the grounded pole 15 or crossarm.
FIGS. 3 and 4 illustrate an alternative cutout cover 40, also invented by the Applicant. There are no sidewalls near the end of the cover 40, and the roof over the hook assembly and pull ring is flat, so that the hook assembly and pull ring of the cutout may be accessed through a wide range of angles by a load break tool. The cover 40 is formed of a resilient dielectric. The cover 40 is similar to the cover 32 in that it has a vertical slot 42 in back and a top hole for the wire 16 (FIG. 1) so the cover 40 can be slid over the cutout while the wire 16 is connected and energized. Since the slot 42 is resilient and faces the pole 15 or crossarm, squirrels can easily push nuts through the slot 42 to pack the cover 40 with nuts.
FIG. 4 shows the cover 40 installed over a cutout 10.
After the cover 40 is in position, pins 46 and 48 are pushed through holes 50 and 52 (FIG. 3) to keep the cover 40 in place during high wind conditions. The pins 46 and 48 extend under the cutout connector 18 and top contact 20.
FIGS. 5 and 6 illustrate front and side views of the plastic pin 46. The pin 46 has a ring 48 for grabbing with a hot-stick. A resilient tip 54 enables the pin 46 to be easily pushed through the hole 50 (FIG. 3), but makes it more difficult to be removed due to its differently sloped sides.
Other types of dielectric covers are installed over high voltage bushings and insulators to prevent wildlife contacting any high voltage conductors. One such cover covers the high voltage coupling between a wire and an insulator, where the wire conducts electricity to a transformer. Such covers may also have the rear vertical slot and hole to enable the cover to be installed while the wire is connected and energized. Such covers also have the problem with squirrels cramming nuts through the resilient slot, since the slot faces the utility pole.
What is needed is a device that can be easily installed over existing installed covers to prevent squirrels cramming nuts through the resilient rear vertical slot. Such a device should also be able to be packaged with the covers using the existing packaging.